Have you seen an instance of this happening to someone who did not return multiple large purchases? I am worried about this happening, but in every instance I read about, the person who got banned had returned multiple TV's or computers, not small items. However, the ebook return policy has only been in place for around a year, so it might not show up.

With ebook returns, it seems like they only disallow you from refunding ebooks in the future, but do not ban your account